Mortar-box for stamp-mills.



PATENTED JAN. 21, 1908.

D. A. BREMNBR. MORTAR BOX FOR STAMP MILLS.

APPLICATION FILED JULY 31. 1905.

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Np. 877,291 D. A. BREMNER.

MORTAR BOX FOR STAMP MILLS.

APPLICATION FILED JULY 31.1905.

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APPLIOATION FILED JULY 31.1905.

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PATENTED JAN. 21, 1908.

D. A. BREMNER. MORTAR BOX FOR STAMP MILLS.

APPLICATION FILED JULY 31.1905.

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N D S MORTAR-BOX FOR STAMP-MILLS.

Specification of Letters Patent.

Patented Jan. 21, 1908.

Application filed July 31.1905- Serial No. 272083.

T 0 all whom it may concern:

Be it known that I, DAVID ALEXANDER BRENNER, a subject of the King ofGreat Britain and Ireland, residing at London, England, have inventedImprovements in Mortar-Boxes for Stamp-Mills, of which the following isa specification.

This invention relates to mortar boxes for stamp mills, such as are usedfor crushing mineral ores and other substances, and its objects are toexpedite the discharge of the crushed material, to prevent theaccumulation of crushed or partially crushed material in the vicinity ofthe end stamps and the choking of the feed mouth by the lodgment ofmaterial therein, to facilitate the removal and replacement of thescreen and of the in terior linin s of the box, and to reduce thewastage of lining material.

In the accompanying drawings Figures 1 to 3 illustrate the applicationof this invention to a mortar box constructed with a removable front inaccordance with Morisons British Patent No. 10890 A. D. 1901 and UnitedStates Patent No. 755,913 of March 29, 1904 and fitted with a verticalscreen. In Fig. 1 the left hand half is a front elevation of the boxwith the front, screen, and chuck block removed, and the right hand halfis a section on the line BC of Fig. 2, one end die being, however,.shown in elevation. Fig. 2 is a plan view, showing the screen and thefive dies in position. Fig. 3 is a transverse section on the line D E ofFig. 2 the dies being, however, shown in elevation. Figs. 4 and 5 aresimilar views to Fig. 3 showing this invention applied to other types ofmortar boxes.

Referring to Figs. 1, 2 and 3, in this example the feed mouthj extendspractically from center to center of the end stamps coinciding with thecenters of the two dies 0 at either end of the box as shown in Fig. 2.The upper edges 9 of the opening in the back wall a of the body of thebox A, communicating with the feed mouth, j, is at a higher level thanthe outer lip h of the latter so that the entering material beingunconfined on the side nearer the stamps, will not lodge in the feedmouth and to check the ejection of crushed material and water throughthe feed mouth 3', a swinging or flexible screen or partition 2 ofcanvas, leather, or other suitable material is suspended from theoverhanging wall a of the box, to which it is attached by means of thefiat iron clamping bars 2 and bolts a the screen 2 may advantageously bevertically sub-divided into a number of independent sections so that thepassage of material under it at one point may not displace the entirescreen and possibly create open spaces through which splashes of pulpmight be ejected.

In Figs. 13 the lower and thicker por tions of the back wall a and theend walls a of the body of the box A are vertical up to a heightcorresponding approximately to the top of the opening in the screenframe 8. In the direction of the length of the box, the back wall abelow the feed opening j, is straight throughout a distancecorresponding approximately to the inside length of the latter betweenits end walls a. Each end wall a of the box is straight in the directiontransverse to the length of the box, from the screen seating flange 0 toa point corresponding with the longitudinal center line of the stamps.At either end of the box the inner face of the wall extending betweenthe contiguous ends of the aforesaid straight back and end walls, is aconcave cylindrical surface embracing an angle of 90 struck from thecenter of the adjacent end stamp, at a radius equal to the perpendiculardistance therefrom to the inner face of the back wall a of the box, andto which cylindrical surface the inner surfaces of the straight back andend walls are tangential. The aforesaid curved walls may, however, becurved to a larger radius than that specified above and shown in theaccompanying drawings, in which case the curve would be struck from acenter located on the screen side of the center of the adjacent endstamp, and the wall of the box may be entirely curvilinear from the endof the straight back wall round to the screen seating flange, or thecurvature may be of increasing radius towards the latter.

The desired object of gradually deflecting the wave of pulp from theback of the box around the end stamps and out through the screen can beaccomplished by either of the above mentioned alternative constructions.

A further advantage resulting from the above described formation andproportions of the interior of the box is that the screen openingextends well beyond the end stamps, and that the edges at each endthereof can be made flush with the wearing faces of the end linerscontiguous thereto throughout the full height of the latter, thusobviat- 1 ing the formation of shoulders or opposing surfaces tending tocheck the discharge of may be made to overh pulp from the extreme endsof the box.

At each end of the box an inwardly projecting rib b is cast on orattached to the inner face of the walls, at such a height that itsunderside is approximately level withthe top of the opening in thescreen frame 8. Below each rib b is inserted a cast steel segmentalliner K curved to conform to the curvature of the contiguous wall a ofthe box casting, and extending around from the inner face of the screenseating flange c to the inner face of the corresponding end wall n ofthe feed mouth 3'. The liners K are flanged inwardly at top and bottom,the upper flange Z projecting beyond the edge of the rib b to'protectthe latter from wear, and the lower flange being shaped to fitaround thebase of the adjacent die 0 and prevent displacement of the latter. A bara of cast steel or other suitable material is placed in the back bottomcorner of the box, and extends lengthwise between the edges of the endliners K which it assists to retain in position. This bar it also actsas a stop to check lateral displacement of the dies 0, 0 The bar it islaid on the bottom of the box against the back wall of the latter, andinserted between the lower ends of the end liners after the end linershave been placed in position.

The sloping bottom of the feed mouth 9' and the corresponding straightportion of the back wall a ofgthe box A are protected from'wear by thecast steel liner plates m, m m m riveted on to mild steel apron plates4) which are bent to conform to the shape of the underlying surfaces andpreferably hook on to the-outer lip 72 of the feed mouth y' from whichthey are suspended. For convenience of handling, the apron plates andliners are subdivided into four separate. and interchangeable parallelsections, each of which extends from the lip h of the feed mouth j downto the top of the bar it. The end walls of the feed mouth j areprotected by liners n which hook on to the edges thereof.

The shape and dimensions of the feed mouth and the feed opening in theback wall a of the box, are such that the lining described above can bereadily withdrawn from or inserted into position through the feed mouth,and its suspension from the lip of the latter obviates the use of boltsor other fastenings to retain it in position. The linings may bemadeofcast steel, steel plate, or other suitable material, and are securedby rivets or other means so as to enable any individual wearing plate,which may have become so badly worn as to require renewal, to be readilyremoved and replaced by a new plate, without involving the wastage ofconsiderable unworn portions of the liners. For the purpose of forming acontinuation along theyback of the box of the inwardly projecting flangeZ the wearing plates m ng the\wearing plates m as shown.

As will be obvious, the use and advantages 7 of such a construction anddisposition of linings are not restricted to mortar boxes of theparticular form and proportions hereinbefore described. They may, forexample, be applied to mortar boxes in which the corners are eithersquare or curved to a comparatively small radius.

The screen 0 the edges of t e screen seating flanges c, c are flush withthe inner faces of the contiguous portions of the end liners K, so thatthere are no shoulders or other opposing surfaces to retard thedischarge of the pulp through the screen at each endof the box.

The screen frame 8 is held up to the face of the seating flanges c bywooden filling blocks 25 and screws 1" working in threaded gunmetalbushes g su ported in holes in the flanges 6 formed on t e extensions aof the end walls a of the box casting A. The filling blocks t are eachfitted with a metal backing t to take the pressure of the screws r. Thethreaded ening is of such a length that bushes q are made with ahexagonal flange at the end nearest the screen 8, and are so locatedthat when in position a cant or facet of the flange closely approachesthe face of the adjacent wall a the box casting, the bush being therebyprevented from turning. The screws rare made with long single endedhandles 19 and the bushes g are so adjusted that, when the screws aretightened up to the filling blocks t, their handles lie on the righthand side of the vertical position. Under the influence of vibration themovement of the handle about the axis of the screw tends to turn thelatter, and keep it tightened up against the filling block 25. When,owing to wear or other cause, the screw be-. comes tight when the handleis on the left hand side of the vertical position, it can be readilyrestored to its self tightening position by removing the screw andfilling block from their places, drawing the bush g out of its seat,turning it round and re-inserting it in the required position. It willbe obvious that there are a variety required position.

The screen is preferably held in a vertical position and as close to thestamps as may be conformable with the other constructional requirements;such a disposition of the screen having been found in practice toconduce to a rapid discharge of the crushed material.

The discharge lipf of the box A is protected from wear by the linerplate 2 attached to the chuck block 3 WVhen the position of the screen 8is such that-the top bar of the screen frame does not overlap t e jointface at the bottom of the removable front w, the filling board x isinserted to make the joint.

of means whereby. the bush may be adjusted and held in any To check theuseless splashing of the pulp up past the screen 8, a metal baffle plateor deflector 9c is attached to the top bar of the screen frame. Wherethe proportions of the box and stamps require it, as in Figs. 1 to 3,

thebaflie plate 00 is scalloped out to fit round the. stam heads.

Fig. 4 1 lustrates the application of my invention to a mortar box withan inclined screen 8 and an oppositely inclined removable front w. Inthis case the filling blocks t shown in Figs. 1. to 3 are dispensed withbecause, when the screws 7" are slackened, the screen 3 can be freelyremoved upward, if the tail nuts (1 on the lowermost of the doorfastening bolts (1 be turned into the required position.

Fig. 5 illustrates the application of my invention to an ordinary mortarbox, in which the front wall w above the screen 0 ening is integral withthe box casting A. n this case also the filling blocks t are dispensedwith because there is no obstruction to the upward removal of the screen8 as soon as w the screws p are slackened.

What I claim is 1. In a stamp mill having a series of stamps, a mortarbox with a screen opening at the front, and solid end portions eachformed inside with curved concave surface of considerable radius adaptedto guide the pulp round the end stamps towards the front of the box, asset forth.

2. In a stamp mill having a series of stamps, a mortar box with a screenopening at the front and solid ends comprising front portions theinternal surfaces of which are perpendicular to the back wall andintermediate portions having concave internal surfaces curved to aradius approximately equal to the distance between the center of theadjacent end stamp and the back wall of the box, said curved andperpendicular surfaces being adapted to guide the pulp round the endstampsand towards the front of the box, as set forth.

3. In a mortar box having a screen opening in its front wall, a backwall which is practically vertical to a height corresponding to the topof the screen opening, a feed opening in said back wall and a feed mouthwith a sloping bottom, linings extending over said bottom, through thefeed opening and over the corresponding length of the said back wall ofthe box below the tops of the dies, said linings being adapted to bewithdrawn from and inserted into position through the feed mouthopening, as set forth.

4. In a mortar box having a screen open ing in its front wall, a backwall which is practically vertical to a height corresponding to the topof the screen opening, a feed opening in said back wall and a feed mouthwith a sloping bottom, linings extending over said bottom, through thefeed opening and over the corresponding length of the said back wall ofthe box below the tops of the dies, said linings being adapted to bewithdrawn from and inserted into position through the feed mouthopening, end liners for the end walls of the box and a bar extendingalong the back of the box and engaging with the lower parts of the backand end liners, as set forth.

5. A mortar box having a feed opening in the back wall thereof and afeed mouth with sloping bottom wherein said bottom and the correspondinglength-of the back wall are lined with an apron plate and renewablefaces detachably secured thereto, said apron with attached faces beingadapted to be withdrawn from and inserted into position through the feedmouth, as set forth.

6. A mortar box having a feed opening in the back wall thereof and afeed mouth with sloping bottom wherein said bottom and the correspondinglength of the back wall are lined with an apron plate and renewablefaces detachably secured thereto, said apron with attached faces beingadapted to be withdrawn from and inserted into position through the feedmouth and the said apron plate being adapted to hook over the lipthereof, as set forth.

7. In a mortar box, the combination of internal ribs upon the end'wallsof the box, end liners inserted beneath said ribs and a bar extendingalong the back of the box and engaging with the end liners and retainingthem in position, as set forth.

8. In a mortar box, the combination of internal ribs upon the end wallsof the box, end liners inserted beneath said ribs and a bar extendingalong the back and at the bottom of the box and engaging with the lowerparts of the end liners and retaining them in position, as set forth.

9. In a mortar box, the combination of internal ribs upon the end wallsof the box, end liners inserted beneath said ribs, a bar extending alongthe back and at the bottom of the box and engaging with the end linersand retaining them in position and, at the back of the box, liners thelower edges of which engage with said bar, as set forth.

10. A mortar box wherein the screen frame is held up to the joint facesby means of screws supported in extensions or lugs, which screws areconstructed with unbalanced handles and mounted in threaded bushesadapted to be set in suchwise that,

when the screws are tightened up, the

in said bushes and adapted on rotation to move towards or from the jointfaces, and unbalanced projections on said screws, as set forth.

12. In a mortar box, a screen opening, joint faces around same,angularly adjustable threaded bushes mounted in abutments, means forfixing said bushes in given adjusted angular positions, screws mountedin said bushes and adapted on rotation to move towards or from the jointfaces, and unbalanced handles on said screws, as set forth.

13. In a stamp mill having a series of stamps, a mortar box With solidend portions formed inside with curved concave;

surfaces and a screen opening in the front of such length that the edgesof the screen seating flanges are flush with the inner concave surfacesof the ends of. the box, the curvature of said concave end surfacesbeing of considerable radius and adapted to guide the pulp round the endstamps and outwards through the screen opening, as set forth.

Signed ,at West Hartlepool, England this twentieth day of July 1905.

DAVID ALEXANDER BREMNER.

Witnesses:

FREDERICK VYM. LANDALE, JOHN WVILLIAM WALTON.

